Retractable blast deflector fence



Nov. 28, 1961 A. PHILLIPS ETAL 3,010,684

RETRACTABLE BLAST DEFLECTOR FENCE Filed Dec. 2, 1959 m Em! A. Phllhps1,2? RicrMltJBMolt,

2/9 in 02 3 90 ATTORNEY United States Patent 3,010,684 RETRACTABLE BLASTDEFLECTOR FENCE Earl A. Phillips, La Grange Park, and Richard P. Molt,Olympia Fields, 111., assignors to Stanray Corporation, a corporation ofDelaware Filed Dec. 2, 1959, Ser. No. 856,847 3 Claims. (Cl. 244-114)This invention relates to improvements in blast fences for deflectingthe very high temperature, high velocity jets of gas and air exhaustedfrom the nozzles of reaction motors of modern jet aircraft while on anairport apron during warm-up and ground testing of such engine, and atthe end of a nlnway during takeofi. Such exhaust blasts frequently causehazardous conditions to persons and equipment in the immediate vicinityof the aircraft. Jet engines are vulnerable to dust, dirt, and otherobjects which may be pulled into their intakes. Thus the blast from onejet engine may cause objectional matter to be hurled toward the intakeof another such engine to the detriment of the latter.

It is the object of this invention to provide a perforated or solidblast fence which may be located in and transversely of the path of theexhaust blast from a jet engine, and which, when solid, redirects theblast upwardly and rearwardly over the fence, and which, when perforatedwill break up the blast and direct some of it upwardly and rearwardly,and some of it through openings in the fence, thereby causing aturbulence behind the fence which will dissipate the force of the blastand allow it'to escape harmlessly. The perforated fence is the preferredform because it products a more dissipative action on the blast;however, in the case where additional protection is desired immediatelybehind the fence, the perforations may be reduced in number and size, oreven eliminated completely, depending on the degree of protectionrequired. The dimensions of the fence preferably should be such that theupper edge, when in operative position, will be at a higher level thanthe path of travel of the blast, so that the entire blast will hit thefence. It should preferably be higher also than the height of personswho may be behind the fence, proceeding to or from an adjacent aircraft.

Such fences, especially those installed at the end of a runway toprevent the blast from planes during takeoff from blowing debris overthe airport boundaries onto highways usually running alongside theairport, sometimes interfere with the landing of planes on the runway.It is therefore another object of the invention to provide such a fencehaving a supporting structure which may be retracted to lower the fencefrom an upright to a horizontal position as required, especially duringthe landing of incoming planes.

Other objects and advantages of the invention will appear in thefollowing description thereof.

Referring to the accompanying drawings forming part of this application,and wherein like reference characters indicate like parts:

FIGURE 1 is a perspective view of the rear of a length of blast fenceshowing the retractable feature of the supporting structure of thefence.

FIGURE 2 is an end elevation of the fence shown in FIGURE 1 with theretracted position shown in solid lines, and the elevated position shownin dotted lines.

In the drawings, the fence is made up of a plurality of modular units12, which are rectangular sheets of metal, bent into a slightly arcuateform as shown. Each unit is provided with side flanges 14, the meetingflanges of adjacent units being secured together in any desired mannerso that a fence of any desired length may be provided by merelyassembling the desired number of the units together. The units may beperforated as indicated at 13 so ice 2 that part of the air blaststriking same will be directed upwardly and over the fence and part willpass through the openings and be broken up and dissipated behind thefence.

It is not imperative, however, that the units be perforated aspreviously explained.

An angle iron 16, or other suitable structural member, is secured acrossthe rear of the units adjacent the top of the fence, and a similarmember 18 is secured across the rear of the units adjacent the bottom ofthe units. These structural members provide added rigidity to theassembled modular units 12.

A frame structure to support this fence is provided, comprising a pairof angle iron members 2020 disposed normal to the rear of the fence,spaced inwardly from the sides of the fence and adapted to rest upon theground when the fence is in use. One of the flanges of said anglesextends upwardly, and against this flange of each angle at the endadjacent the fence is secured the lower margin of a triangular plate2222. The apex of each triangular portion 22-22 extends between spacedflanges 2424 of angle clips secured to angle member 18, and said apicesare pivotally secured on a horizontal axis to said clips as at 25.

Across the rear lower margins of the modular fence units 12, immediatelybelow flanges 24-24, is a substan tial concrete or other counterweightindicated at 26. The bottom surface of the counterweight is chamfered atan angle so as to be in plane with and rest upon the ground when thefence is in upright position. Being of substantial weight and below thepivotal point 25 of the fence to the framework, the counterweighteffectively balances the fence across pivot 25 and therefore reduces toa minimum the power required for elevating and lowering the fence andcorrespondingly reduces to a minimum the sizes of the various elementscomprising the elevating and lowering mechanism.

Between the angles 2020, about midway between the ends thereof, extendsa brace 28 which is secured at its ends to said angles '2020. At theouter ends of these base angles 2020 is a second bracing member 30extending therebetween and secured at its ends to said base angles. Uponthe ends of this second bracing member 30 is a pair of pillow blocks32-32, within which are journaled the ends of shaft 34. Approximatelycentrally disposed on this shaft is a pinion gear 36 which meshes with arack 38 on the end of piston shaft 40, extending within air cylinder 42to a piston reciprocable therein upon application of a source ofcompressed air, not shown, thereto. Air cylinder 42 is secured to thebrace member 28 to efiectively hold it in position with the rack 38 inmesh with pinion 36. Obviously instead of the air cylinder 42 a motormay be substituted driving a worm gear meshing with pinion 36 andaccomplish the same purpose.

Pivotally mounted within clips 4444, secured within angle 16, are theupper ends of brace rods 46-46, the opposite ends of which are pivoted,as at 48, to the base angle iron members 2020. Intermediate of the endsof the brace rods 4646 they are each provided with a knuckle joint 5050,each arm 46 being in two parts pivotally joined at 54). The upper endsof the lower part of arms 46 are provided with couplings 52 appliedthereto by welding and the upper ends of the coupling are cut away sothat the lower ends of the upper part of the arms 46, pivoted thereto,may jackknife when the fence is re tracted as shown in FIG. 2.

For raising and retracting the fence, there are provided push rods 54,the upper ends of which are pivoted to the knuckle joints 50, as at 56,by means of bifurcated sleeves 58, screw-threadedly applied to the upperends of said rods 54. The lower ends of rod 54 are also screwthreadedlyapplied to bifurcated sleeves 60, the bifurcated ends of which arepivotally attached to one end of the 3 crank arms 62, the other ends ofwhich crank arms are in turn secured to the ends of shaft 34; Thebifurcated sleeves 58 and 60 are shown as screW-threadedly applied tothe ends of push rods 54 and which permits a small adjustment in thelength of rods 54 within the limits of the screw-threaded portion ofthesleeves. However, these sleeves may be rigidly fixed to the ends of therods 54' if preferred.

Thus when it is desired to retract or lower the fence from operativeposition as shown in FIG. 1 to retracted or inactive position .as shownin full lines in FIG. 2, the motor 42 is started so' as to retract rack38, which. causes the pinion 36 to rotate counterclockwise. This in turnwill cause the crank arm 62 to' forcerods 54 against the knuckle jo nts50, resulting in the'knuckles jackknifing and the fence itself rotatingon the pivotal points 25 until in. the position shown in solid lines inFIG. 2. In this position, if the fence perchance isinstalled at the endof a runway, there would be no interference with the landing of incomingplanes. a

From the foregoing it will be seen. that we have provided by thisinvention a blast fence composed of a plurality of identical units whichmay be retracted out of the Way of incoming aircraft and which havecounterweights to minimize the size and power required of the retractingmechanism.

We claim:

1. A blast fence for use transversely of an airport runway in deflectingand dissipating the blast from a jet engin'e, said fence comprising aplurality of modular units secured together at their sides to therebyform a composite fence, acounterweight secured to said fence along thelower margin thereof, means pivotally supporting said fence at an angleto the horizontal, said pivotal support being on a horizontal axis abovethe counterweight, means comprising joined supporting arms for movingsaid fence on its pivotal support, and means for folding'said arms andthereby retracting said fence on its pivotal support toward horizontalposition. i

2. A blast fence for use transversely of an airport run- .way indeflecting and dissipating the blast of a jet engine,

a supporting structure for said fence to maintain said fence in anupright position at an angle to the horizontal or retracted to asubstantially horizontal position, counterweight means biasing saidfence toward its upright position, mean pivotally supporting said fencein either of said positions on an axis adjacent to and parallel with theground-engaging edge ofsaid fence, bracing arms attached at one end tothe upper margin of said fence and at the other end to said supportingstructure and foldable intermediate their ends for lowering said fenceto a substantially horizontal position, andpower means for folding saidarms to retract the fence on its pivotal support to a substantiallyhorizontal position, ,or extending said arms to support the fence in itsupright position.

3. A blast fence for use transversely of the blast from a jet enginecomprising a supporting framework to pivotally support said fence in anupright position at an angle to the horizontal or retracted to asubstantially horizontal position, said pivotal support being on an axisparallel to and spaced from the ground-engaging edge of said fence,counterweight means biasing said fence toward its upright position, saidframework comprising foldable bracing arms to hold said fence in aselected position, means to fold said arms'for lowering said fence to asubstantially horizontal position, said latter means comprising rods topush said arms to folded position, or pull said arms to supportingposition, and power means to operate said rods.

References Cited in the file of this patent. UNITED STATES PATENTS OTHERREFERENCES Popular Science, October 1956, pages 126- 127." AviationWeek, April 8, 1957, page 74.

